Abstract
The background to the failure of the December 2001 Fifth Review Conference of the Biological and Toxin Weapons Convention (BTWC) to agree a politically binding final declaration is discussed. Negotiations in the Ad Hoc Group (AHG) of the BTWC, which was set up after the 1994 Special Conference, are described. Accusations of non‐compliance with the BTWC are not new and it is concluded that the ultimate failure of the 2001 Review Conference was principally, but not entirely, due to rejection by the United States that the AHG should remain in being. Strengthening the BTWC remains as important as ever, but it remains to be seen if there is the political will to achieve this.